Apparatus for drying fabric



1951 H. w. BUTTERWORTH, JR, ETAL 2,570,318

APPARATUS FOR DRYING FABRIC 2 Sheets-Sheet 1 Original Filed NOV. 9, 1942HTTORNEY Oct. 9, 1951 H. w. BUTTERWORTH, JR, ET AL 1 APPARATUS FORDRYING FABRIC 2 Sheets-Sheet 2 Original Filed Nov. 9, 1942 :lii

Patented Oct. 9, 1951 UNITED STATES 'l' FFICE APPARATUS FOR DRYINGFABREC Original application November 9, 1942, Serial No. 465,034.Divided and this application July 19, 1945, Serial No. 606,014

5 Claims.

This invention relates to an apparatus for drying and conditioningtextile fabrics. While the invention will be described more particularlyin connection with the treatment of tubular knit rayon fabric, it may beutilized in handling knit, tubularized woven and fiat knit and wovenfabrics of rayon and fibers other than rayon to afford similaradvantages.

Almost all textile fabrics, more particularly knit goods, while in theprocess of being dried, will either elongate or shrink of their ownaccord in their various dimensions. Knit fabric, and especially rayonfabric, is by nature very elastic and subject to distortion in handlingunless special precautions are taken. This condition is particularlypronounced when the fabric is wet and it is both difficult to keep thefabric in fiat condition free from wrinkles as well as to dry samewithout subjecting it to stretch. The wet fabric may, for example, ifsubjected to stresses during drying, be stretched beyond its elasticlimit, with the result that a permanent set occurs in the individualfibers of the yarn and in the stitches. This results in diflicultybecause the finished fabric is non-uniform with respect to the naturalstitch formation and the distortion of the wales or cross-lines, and itis impossible by further treatment to eliminate the distortion.Consequently, tension should be avoided in drying, to afford the fullelasticity of the fabric in length and width when it is completed and toinsure the proper appearance of I the finished fabric.

Furthermore, it is desirable to avoid over-drying of the fabric which inits finished condition normally contains a given percentage of moisture,depending to some extent upon the nature of the fiber used. Theappearance and hand of the fabric depend upon the retention of thenormal moisture content. If it is over-dried, the moisture content maybe normalized by steaming, but it is preferable to conduct the dryingoperation so that a proportion of moisture remains in the fabric as itleaves the dryer.

In some types of dryers the forming of wrinkles results in non-uniformdrying and over drying. Again, the method of propulsion of the fabricstends in many cases to create tension. In the loop or festoon type ofdryer wherein the fabric hangs in loops from movable slats of a conveyor'which carries the fabric through the drying chamber, beside the factorof uneven drying due to wrinkles and folds, the moisture present in theloops of fabric is sufliciently heavy plus the weight of the fabricitself, to create tension and the fabric is stretched unevenly,

It is the object of the present invention to provide a method of dryingfabric wherein the fabric is supported and is advanced through thedryer, wherein it will either shrink or elongate of its own accord, inits various dimensions, naturally without creating any tension While themoisture is removed progressively and uniformly from the fabric,maintained in flat condition without wrinkles.

Another object of the invention is the provision of a method of dryingin which the amount of moisture removed can be controlled easily toinsure delivery of the fabric, properly conditioned, that is to say witha residuum of moisture which is adapted to closely approximate thenatural moisture content of the fabric.

It is the further object of the invention to support the fabric as muchas possible While it is being advanced and to allow the fabric itself tocontrol the speed of the various reels over which it is progressed, topermit the natural shrinking or elongating of the fabric to take place.I

A further object of the invention is the provision of a dryer affordingmeans for advancing the fabric uniformly without tension and ofdelivering thereto large volumes of air in such a manner as toprogressively remove the moisture content of the fabric to the desiredextent.

A further object of the invention is the provision of apparatus in whichthe fabric is advanced at an automatically controlled linear speed withautomatic control of the various elements which carry the fabric so asto prevent the application of tension at any portion of the fabric.

A further object of the invention is the provision of a drying apparatusin which the air feed can be adjusted with respect to the width of thefabric so that the apparatus may accommodate fabric of varying widthswithout loss or waste of air supplied.

Other objects and advantages of the invention will be apparent as it isbetter understood by reference to the following specification and theaccompanying drawings, in which Fig. l is an enlarged vertical sectiondiagrammatically illustrating the progress of the cloth over the dryingreels and showing the driving mechanism for the reels;

Fig. 2 is a plan section illustrating details of the driving mechanism;

Fig. 3 is an elevation partially in section of the mechanism shown inFig. 2;

Fig. 4 is an enlarged sectional view illustrating the variable speedmechanism; and

Fig. 5 is a diagrammatic view illustrating another arrangement of theinlet and outlet ducts for distributing air to the dryer.

As hereinbefore indicated, the invention depends upon the conveyance ofthe fabric at an automatically controlled linear speed at all sectionsthereof through the drying compartment wherein it is subjected to alarge volume of air at high velocities applied and distributed so as toeffect the maximum desired drying effect at an accelerated rate. Inaccomplishing this purpose, we have provided a drying chamber in which aplurality of reels are mounted for rotation and adapted to support thefabric as it advances through the dryer. Preferably each of the reelssubsequent to the first is driven through an automatic speed controllingmechanism, and the fabric is advanced over the series of reels withoutsubjecting it to any tension. As the fabric advances, a large volume ofair which may be heated to the desired temperature, is introduced anddistributed at high velocities so.

that it is directed against and passes through the fabric and iswithdrawn through a duct at the end of the reel. This air bearing aproportion of moisture removed from the fabric may be recirculated invarious ways, with or without the addition of fresh air, depending uponthe amount of drying desired, the nature of the fabric, and the amountof moisture to be Withdrawn therefrom.

Instead of withdrawing the air carrying mois-' ture from all of thereels and returning the air to the air inlet, the method may be operatedso that the air withdrawn from the first reel is delivered through asupplemental blower to a second reel and so on through the apparatusuntil the air is finally withdrawn from the last reel, after which itwill have done all of the drying of which it is capable. In thisprocedure, the air undergoes a gradual temperature drop from reel toreel, and its relative humidity is greatly stepped up from reel to reel,so that by the time the air leaves the last reel its temperature, due toevaporation, is very low as compared to its original temperature, andits relative humidity is quite high, due to the moisture which has beenabsorbed in traveling through the fabric.

The same general result may be accomplished by employing two or moreconsecutive units for drying and delivering the air withdrawn from theseveral individual reels of the first unit to the reels of the secondunit without intermediate heating or separation of moisture. Thus, inthe second unit, through which the fabric passes, it is subjected toconditioning due to the higher moisture content of the airintroduced'thereto;

Other variations of the method may be employed, the fundamentalcondition being that the fabric is supported and advanced in a flatsmooth condition without being subjected to tension and as it isadvanced a large volume of air at high velocity is directed against thefabric, the tem' perature and moisture content of the air being adjustedin various ways, such as the introduction of fresh air, to insuredelivery of the fabric free from surplus moisture. Since the weight ofthe fabric itself while being advanced and the moisture it contains arefactors inducing tension, they are off-set by the considerable suppor}:given to the fabric in its position on each ree While details of theapparatus may be varied in carrying out the invention, we prefer theapparatus hereinafter described. Referring to the be varied. We preferto employ an even number,

but an odd number may be used.

The fabric I8 before entering the dryer may pass over one or morerectifiers as more fully described in application Serial No. 190,830,now Patent No. 2,198,656, to remove all wrinkles while being spread tosmooth, flat condition, or over a spreader unit as more fully describedin Patent No. 2,130,118 and then enters the top of the dryer over acylinder II which is driven in a manner hereinafter described, so thatits peripheral speed is synchronized with that of thefirst reel 6.

is delivered from the bottom of the dryer. As

hereinbefore stated, each of the reels 6 is driven,

and its speed of rotation is varied continuously so as to avoid anytension in the fabric as it passes from reel to reel.

Air is introduced, preferably at high velocities,

by blowers preferably disposed at both ends of the dryer through ducts13 to distributors l4 having semi-cylindrical faces [5 disposed'aboutthe surfaces of the respective reels. 7 faces l5 are provided witha'multiplicity of 1102 zles [5 which direct the air onto the fabric asit;

power, such as a variable speed motor 29 having a pulley 30 thereonconnected by a belt 3| to a pulley 32. A fiat belt 33 extends about thepulley 32 and upward to a pulley 34 at the top of the dryer. The latterpulley is mounted on an arm 35 pivoted at 35 and adjustable by meansof'a' tension device or spring 31 and a screw 38, so

that the tension on the belt 33 is uniformly maintained. The high speedbelt 33 drives combina tion V and flat belt pulley 39 by short arecontact. drives pulley 40 through V belt 4|. fastened to the input shaftof the reducer 4!.

The'output shaft of the reducer is direct coupled to reel 6. This sameoutput shaft carries pulley 42 which drives to combination pulley andgear- 43 through V belt 44. The gears 43, 45 reverse rotation and thedrive continues through combination gear and V belt 46 to pulley 4'! onthe shaft of the cylinder I I.

the peripheral speed of the first reel 6 is identical with that of thecylinder I l, and no tension can" be exerted on the fabric as it entersthe dryer.

Each of the subsequent reels 6 is driven bya variable speed mechanismwhich is illustrated in detail in Figs. 2 to 4 inclusive of the drawing.A" description of one of these mechanisms will serve for all of thesubsequent reels, the peripheral speeds of which are adjustedautomatically by themechanism to control the tension of the fabric.

Pulleys 48 and 50 are fastened together having a suitable common bearing50' and revolving on a The fabric passes around the first reel: 6 andthence around the succeeding reels and- The sur The V groove andcombination pulley 39'- Pulley 40 The connections are such thatstationary shaft 49. Pulley 59 through belt 51 drives a pulley 52fastened to revolving shaft 53 which also carries a variable speedpulley 54 of the type illustrated and described, for example in PatentNo. 2,050,358. This pulley, as illus trated in Fig. 4., comprises amember 55 which is biased toward a cooperating member 56' by a springbearing against a cap 58 which rests upon a shoulder on the end of thestub shaft 53 and is held thereon by a nut 59. The member 55 ispermitted to move toward and'from the member 56, permitting the V-belt66 to move toward or from the stub shaft 53, thus yarying the pitch ofthe pulley. The'v-belt 69 i connected to a pulley ti on a shaft 52 of aspeed-reducing mechanism 53, the details of which form no part of thepresent invention and are not illustrated. The output of thespeed-reducing mechanism 63 is the shaft l of the reel 6.

To accomplish the speed variation, a dancer roll as is mounted on an arm55 which is secured to a shaft 65 mounted in a bearing 6? inthe sidewall of the dryer. The dancer roll 64 is adapted to rest lightly againstthe'fabric [5 as it passes from one reel to the next. Any variation inthe tension of the fabric causes the dancer r0ll64 to move, thustransmitting motion to the shaft 66. Secured to this shaft is aneccentric arm 68 carrying bearings 59 for the stub shaft 53 and also anarm with a counterweight H which is adapted to be adjusted so as tobalance the dancer roll 65, thereby making it sufficiently sensitive forthe purpose.

As the dancer roll shifts the position of the stub shaft 53, therelative positions of the various pulleys will be changed. Any slack inthe belt 5| is immediately taken up by an idler 12 on an arm 1'3 whichis held under tension by a spring 14. Variations in the relativepositions of the shafts 62 and 5-3 will cause, through the variablespeed pulley including the element 55, a change of pitch of the latterpulley and a modification of the speed of the shaft 62 in accordancewith the temporary condition of the fabric l0. Thus, the second reel 6and each of the succeeding reels is subject to an increase or reductionof peripheral speed continuously as the condition of the fabric It]varies. In operation, the dancer roll 64 changes its position to varythe speed of the reel it controls according to the elongation orshrinking of the fabric being handled to accomplish the purpose ofadvancing the fabric without subjecting it to any substantial tension.Thus, on certain fabrics, the speed of the reels may be progressivelyincreased, on other fabrics, the speed of the reels may be alike orwhere shrinkage takes place during drying, one or more of the reelssubsequent to the first may be run at a speed slower than that of thefirst reel. Where elongation of the fabric take place during drying,which may be predetermined, the speed of the reels subsequent to thefirst may be fixed at a progressive increase. In such case, the dancerrolls and the devices controlled by them may be eliminated or may beused to effect such changes in the individual drive of the several reelsas may be necessary to meet the varying conditions which cannot bepredetermined. It is understood that where tension on the fabric isdesired, the dancer roll 64 may be so adjusted as to obtain the tensiondesired.

In Fig. 5 We have illustrated a modification of the apparatus in whichthe drying chamber 5 is provided with reels 6 and distributors It as inthe preceding embodiment of the invention.

The fabric is conveyed through the dryer in-themanner hereinbeforedescribed. In this case, however, air is introduced by a blower 15 tothe first distributor l4" and is withdrawn through a duct 16 receivingthe air through the opening shown in the side of the chamber adjacentthe end of the corresponding reel so that air from the distributor '14passing through the fabric is drawn out through this duct 16, anddelivered by a blower T! to the second reel 6. Thence the air iswithdrawn and returned to successive reels by blowers l5 and 11" untilit is withdrawn through the exhaust 7-8. This arrangement, as we havehereinbefore stated, permits the application of' air, partiallymoistened by passage through the fabric, again to the fabric in theseveral stages. The several reels 6 will be driven so as to avoidstretching the fabric by utilizing the mechanism hereinbefore described.

The uniformity of the method of air application to the fabric is novel.As indicated in the drawings, the air is applied directly to one side ofthe fabric while it is flexed in its curved position around the reel andas the fabric passes on to the following reel, the air is simultaneouslyapplied but to the opposite side of the fabric, thus insuring uniformityof air permeation through the fabric and drying.

It is to be understood that numerous variations of the procedure andapparatus are possible. For example, the fabric may enter the bottom andleave the top of the dryer, the flow of air being as shown or reversed.Also, instead of conveying the fabric transversely from reel to reel, itmay be caused to travel down one side of the dryer and up the otherside, and the delivery of air and the moisture content thereof in thetwo sides of the dryer may be adjusted to effect the drying of thefabric in the desired manner and particularly to leave therein theamount of residual moisture which is required to afford the optimumcondition thereof. Another alternative use of the dryer involves, as wehave stated, the use of two or more units arranged so that the fabricpasses through each unit successively and the air employed in one unitis delivered without further heating or drying to the following unit toeffect conditioning of the fabric.

These and other modifications may be introduced without departing fromthe invention or sacrificing the advantages thereof.

This application is a division of U. S. application Serial No. 465,034,filed November 9, 1942, now Patent No. 2,427,943, which is in turn adivision of U. S. application Serial No. 274,388, filed May 18, 1939,now Letters Patent 2,301,249 granted November 10, 1942.

We claim:

1. In a drying system for fabrics of the class consisting of knitted andwoven textiles a casing, a plurality of rotatable members within thecasing adapted to support and convey a continmm length of said fabric tobe dried and having pervious peripheral structures directly supportingthe fabric alternately first on one side and then on the other andfeeding the fabric while permitting passage of air therethrough, anouter supply of heated air, separate air ducts for said outer airsupply, and a plurality of separate air distributors independentlyleading the said air to each side of the fabric length as it passes oversaid rotatable members and separately receiving the air from said outerair supply through said air ducts and having nozzles adjacent saidpervious peripheral structures passing said air supplies through thefabric on said members alternately from the air distributor nozzles onone side and then from the air distributor nozzles on the other side sothat both sides of the fabric are alternately subjected to the air flowsand. the fabric is evenly dried on both sides.

2. A fabric drying system as set forth in claim 1 in which the casinghas outlets adjacent the sides of said movable members and there ismeans for withdrawing air outward through said outlets.

3. A fabric drying system as set forth in claim 1 in which there are twoseries of air distributors, one series on one side supplying air to thatside of the fabric and the other series on the other side supplying airto the opposite side of the fabric. I

4. A fabric drying system as set forth in claim 1 in which there areindividual air distributors connected in succession on each side of thefabric, the exhaust from each air distributor being connected to theintake of the succeeding air distributor so that the air supply to eachair distributor is recirculated through the next successive airdistributor and the drying air and fabric progress through the apparatusin the same direction.

5. A fabric drying system as set forth in claim 1 in which a distributoron one side has a series of curved faces disposed about a series ofrotatable members within the casing on that side and the separatedistributor on the other side has a series of curved faces similarlydisposed about a series of rotatable members Within the casing on thesaid other side, said curved faces carrying the said air nozzles forsupply of air to the fabric alternately on opposite sides, first fromone distributor on one side and then from the other distributor on theother side, the air for the rotatable members on one side coming fromone distributor on that side and the air for the series of rotatablemembers on the other side coming from the other distributor on the otherside.

HARRY W. BUTTERWORTI-I, JR.

SAMUEL COHN.

MORTIMER COHN.

JULES G. WALTER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 270,992 Snoeck' Jan. 23, 18831,251,173 Beregh, Jr. Dec. 25, 1917 1,287,027 Janson Dec. 10, 19181,427,437 Breuer Aug. 29, 1922 1,470,953 Bassler Oct. 16, 1923 1,576,906Greve Mar. 16, 1926 1,956,062 Duvall Apr. 24, 1934 2,301,249Butterwor-th, Jr., eta1. No 10, 1942 FOREIGN PATENTS Number Country Date647,772 Germany July 12, 1937

